Stimulated raman scattering （SRS） is an effective method for expanding the spectral range of high power lasers, especially in the regime of near IR and middle IR. We report the SRS of high pressure H2 with a multipl...Stimulated raman scattering （SRS） is an effective method for expanding the spectral range of high power lasers, especially in the regime of near IR and middle IR. We report the SRS of high pressure H2 with a multiple-pass cell configuration. The SRS with the multiple-pass cell configuration is found to be very efficient for reduction of threshold of the first Stokes （S1）. Due to the coherent SRS （CSRS） process, the multiple-pass cell configuration is more effective for reduction of the threshold for the second Stokes （S2） SRS and for increasing the conversion efficiency of S2. This contributes to the relatively low conversion efficiency of S1 for the multiple-pass cell configuration. Multiple-pass cell SRS is also found to be very effective for improving the beam quality and the stability of S1.展开更多
Nitric oxide(NO)is cooled to 1 K in a seeded Ar supersonic molecular beam.NO molecules are ionized by one-color two-photon resonant enhanced multiphoton ionization(REMPI)process to form an ultracold plasma.The density...Nitric oxide(NO)is cooled to 1 K in a seeded Ar supersonic molecular beam.NO molecules are ionized by one-color two-photon resonant enhanced multiphoton ionization(REMPI)process to form an ultracold plasma.The density of the ionized molecules in the illuminated volume approaches to 1.5×10^(13) cm^(-3).Prompt electrons,plasma electrons and intact NO+ions are produced during this process.Experimental results confirm that the lifetime of this ultracold plasma is longer than 18.3μs.This is the first report of NO ultracold plasma with significant lifetime produced by one-color two-photon REMPI process.展开更多
In this work, SF6 as a Raman-active medium is investigated to generate a multispectral Raman laser by the combination of cascade stimulated Raman scattering(SRS) and four wave mixing. The Raman frequency comb from the...In this work, SF6 as a Raman-active medium is investigated to generate a multispectral Raman laser by the combination of cascade stimulated Raman scattering(SRS) and four wave mixing. The Raman frequency comb from the 10 th-order anti-Stokes to the 9 th-order Stokes was generated, and its spectral range covered377–846 nm. The photon conversion efficiency of 16.4% for the first Stokes was achieved, and the Raman gain coefficient at 1.5 MPa of SF6 under the 532 nm pump laser was calculated to be 0.83 cm/GW by the SRS threshold comparison with H2. Using helium as the carrier gas, the thermal effect of the SF6 Raman laser was improved dramatically under a repetition rate of 10 Hz.展开更多
Sodium-ethane excimer pairs are studied and proved to be a great choice of excimer pumped sodium laser（XPNa L）gain media.The lifetime of the sodium D2 line is studied in a sodium-ethane excimer system excited by a 5...Sodium-ethane excimer pairs are studied and proved to be a great choice of excimer pumped sodium laser（XPNa L）gain media.The lifetime of the sodium D2 line is studied in a sodium-ethane excimer system excited by a 553 nm laser,and the observed phenomenon of lifetime lengthening is discussed.Amplified spontaneous emission（ASE） of the sodium D2 line is successfully obtained,and its time-resolved and spectroscopic characteristics are studied experimentally.According to the intensity of the ASE signal under different sodium vapor atom densities,the sodium D2 line gain feature of sodium-ethane excimer pairs excited by the 553 nm laser is concluded.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11304311 and 11475177
文摘Stimulated raman scattering （SRS） is an effective method for expanding the spectral range of high power lasers, especially in the regime of near IR and middle IR. We report the SRS of high pressure H2 with a multiple-pass cell configuration. The SRS with the multiple-pass cell configuration is found to be very efficient for reduction of threshold of the first Stokes （S1）. Due to the coherent SRS （CSRS） process, the multiple-pass cell configuration is more effective for reduction of the threshold for the second Stokes （S2） SRS and for increasing the conversion efficiency of S2. This contributes to the relatively low conversion efficiency of S1 for the multiple-pass cell configuration. Multiple-pass cell SRS is also found to be very effective for improving the beam quality and the stability of S1.
基金Supported by the National Natural Science Foundation of China under Grant No 11304311。
文摘Nitric oxide(NO)is cooled to 1 K in a seeded Ar supersonic molecular beam.NO molecules are ionized by one-color two-photon resonant enhanced multiphoton ionization(REMPI)process to form an ultracold plasma.The density of the ionized molecules in the illuminated volume approaches to 1.5×10^(13) cm^(-3).Prompt electrons,plasma electrons and intact NO+ions are produced during this process.Experimental results confirm that the lifetime of this ultracold plasma is longer than 18.3μs.This is the first report of NO ultracold plasma with significant lifetime produced by one-color two-photon REMPI process.
基金the National Natural Science Foundation of China(NSFC)(Nos.11475177 and 61505210)the Key Laboratory Innovation Foundation(No.KLCL-2018-N11).
文摘In this work, SF6 as a Raman-active medium is investigated to generate a multispectral Raman laser by the combination of cascade stimulated Raman scattering(SRS) and four wave mixing. The Raman frequency comb from the 10 th-order anti-Stokes to the 9 th-order Stokes was generated, and its spectral range covered377–846 nm. The photon conversion efficiency of 16.4% for the first Stokes was achieved, and the Raman gain coefficient at 1.5 MPa of SF6 under the 532 nm pump laser was calculated to be 0.83 cm/GW by the SRS threshold comparison with H2. Using helium as the carrier gas, the thermal effect of the SF6 Raman laser was improved dramatically under a repetition rate of 10 Hz.
基金supported by the National Natural Science Foundation of China under Grant Nos.61505210 and 11475177
文摘Sodium-ethane excimer pairs are studied and proved to be a great choice of excimer pumped sodium laser（XPNa L）gain media.The lifetime of the sodium D2 line is studied in a sodium-ethane excimer system excited by a 553 nm laser,and the observed phenomenon of lifetime lengthening is discussed.Amplified spontaneous emission（ASE） of the sodium D2 line is successfully obtained,and its time-resolved and spectroscopic characteristics are studied experimentally.According to the intensity of the ASE signal under different sodium vapor atom densities,the sodium D2 line gain feature of sodium-ethane excimer pairs excited by the 553 nm laser is concluded.
